The present invention relates to elastically deformable bumper systems of the type that are used on boat docks, buildings, transport trailers, and the like. Especially preferred embodiments of the present invention are improved bumper systems for boat docks that serve to cushion the impact of boats against the docks.
Historically there have been many boat dock designs, which utilize some type of elastically deformable bumper cushioning the impact of the boats against the boat dock rigid frame members. Many boat docks are provided with portions of rubber tires nailed to the surfaces that are engagable by the boats when docking at the dock. These rubber tires serve to cushion the impact of the boat against the dock during docking procedures and during the rocking of the boat in the water, while anchored to the dock and also during docking procedures. There are various problems with the use of such tires. First, to many people, the part tires nailed to the docks are ugly and detract from the appearance of the docks. Second, the tires are usually made of some type of petroleum-base rubber or the like, and tend to mar boats rubbing thereagainst, leaving black marks on the boats. Also, the corrosion and wear at the nailing positions of the tire sections to the dock could cause deterioration of the connection and unsightly discolorization of the tires and dock.
In view of the problems with the part tires as bumpers, there have been many proposals for using other types of elastically deformable fenders that are attached to the dock and/or to the boat.
U.S. Pat. No. 4,628,850 to Day et.al. discloses a marine fender arrangement which is adapted to be hung over the side of the boat and/or dock to protect against impacts. This fender has an outer flexible shell and a solid foam bun, and is constructed as a fender which is tied to the boat or dock by means of ropes or the like. Such marine fender arrangements are usually stowed on a boat and are brought out and placed in position only when the boat is docked. This type of marine fender arrangement is inconvenient to use in those situations where frequent boat docking and undocking occurs, due to the necessity to untie and adjust the fenders in position. Furthermore, when leaving the boat dock at a dock for a long period of time, such rope tied fenders become dislodged or are too small to accommodate all of the relative movement positions of the boat, especially in rough weather and/or occasions where significant tidal changes in water depth occur.
There have also been many fixed installations of elastically deformable marine fenders at boat docks, as exemplified by U.S. Pat. No. 3,949,697 to Yueada; U.S. Pat. No. 4,267,792 to Kimura et.al.; U.S. Pat. No. 4,733,992 to Dehlen, and U.S. Pat. No. 4,756,266 to Sakuraoka. These constructions all have various cross-sectional configurations for effecting predetermined desired non-linear deformation patterns. Due to these rather complicated forms, such bumper constructions are rather expensive to construct. Furthermore, in most of these constructions the mechanism for attachment of the fender or bumper at a boat dock or boat is made by bolting flat web portions directly to a boat dock surface at locations spaced from the intentional deformation area of the bumpers.
U.S. Pat. No. 2,890,880 to Hompe et.al.; U.S. Pat. No. 2,926,904 to Erlbacher; and U.S. Pat. No. 3,539,173, are exemplary of multi-part fender or bumper arrangements which are attachable to a boat dock or the like by threaded bolts engaging clampingly with the bumper unit. These bolts are disposed such that they are recessed and are located spaced from the impact receiving surface of the elastic bumper member so as to allow for elastic deformation. These multi-part type arrangements require complicated manufacturing and installation steps. They also place the attachment bolts at relatively thin plate-like portions of the elastic material bumper structure, thereby increasing the risk that large lateral and side collision rubbing forces against the impact surface disrupt the connection of the bumper, since these portions can be torn away.
An object of the present invention is to provide a bumper system which is economical to produce and install, which is reliable and durable in service, which has and maintains a pleasing external appearance, and which performs its bumper functions, without causing discoloration of the bumper or the respective parts being cushioned by the bumper.
According to one aspect of the invention, these objects are achieved by providing an elastically deformable bumper for cushioning impact forces at a relatively rigid member, comprising:
a forward bumper wall member having an impact receiving surface at a first side thereof,
a support web extending from a second side of the forward bumper wall member, said support web terminating in a support web abutment surface adapted for engagement with a rigid member,
and a bumper anchor aperture for accommodating an anchoring device to hold the bumper in position at the rigid member, said bumper anchor aperture extending from the first side of the forward bumper wall member through the support web to the support web abutment surface.
By providing the bumper anchor aperture in the support web which extends from the impact receiving surface back to the abutment surface for engaging the rigid member, such as the boat dock side board or the like, it is reliably assured that the bumper member will not be dislodged by forces acting thereon. In effect, the anchor is at a thick effective structural part of the bumper member, namely at the reinforcing webs. In especially preferred embodiments, the clamping surface of the anchors are disposed at least one-fourth of the distance between the impact receiving surface and the rigid member that it is attached to. In especially preferred embodiments, the anchoring aperture is provided as a countersunk aperture with the clamping surface more than half of the distance of the impact receiving surface to the rigid member that it is attached to, such that the entire bolt or screw head can be completely concealed in this countersunk outer section.
In especially preferred embodiments in the boat dock bumper environment, reflector units are installed in the recessed anchor apertures on top of the anchoring bolt and are still recessed sufficiently from the impact receiving surface so as not to interrupt the elastic deformation impact absorption movement of the bumper system during use. In this manner, the safety of the boat dock is substantially enhanced since these reflectors at the boat dock bumpers serve to forewarn the boat drivers of the position of the bumpers and dock during night boating operations.
In especially preferred embodiments, the elastically deformable bumper member is constructed as a unitary deformable plastic member which has the impact receiving surface at one side of a front wall which is then merged into side walls which extend parallel to the reinforcing webs and thus serve to completely enclose the outer configuration of the bumper when in an installed position. The corners and edges of the bumper member are rounded slightly so as to give a smooth overall appearance to the bumper and so as to accommodate absorption of impacts from all directions.
In especially preferred embodiments, the elastically deformable plastic bumper member is made of "Dupont Alcryn" plastic material, which is especially processed to produce predetermined elastic deformation characteristics. This material is also resistant to sun and other weather aging environmental conditions so that the bumper can be used as a boat dock bumper for many years without deterioration of the appearance or the operation thereof.
Since the bumper can be assembled by a simple screw or bolt attachment at a boat dock or the like, the same can be easily installed even by amateurs.
According to another aspect of certain preferred embodiments of the invention, special corner bumper members are provided which readily adapt themselves to attachment at dock or other structure corners that may not be precisely right angle corner connections or predetermined angle corner connections. To accomplish this corner attachment, the present invention provides a longitudinally extending U-shaped exterior cross-section, with the legs of the U adapted to abut against the boat dock member frame or the like and with the bridge of the U serving as the primary impact receiving surface. In order to accommodate the attachment thereof at irregular angular corner sections, the side walls of the U-shaped bumper member are cut away on the internal side at an angle which exceeds the predetermined desired corner design angle at the rigid frame members to which it is to be attached by between 2 and 10 degrees, preferably between 3 and 5 degrees. For example, for a right angle corner at a boat dock, the angle would be between 92.degree. and 95.degree.. With this arrangement, the bumper member can be attached very firmly along both side walls of the corner section of the dock, with an adjustment range of several angular degrees.
In especially preferred embodiments, the corner members are also provided with extra reinforcement webs from the front impact wall to the cut out section of the edge to thereby further reinforce the corner section, as these reinforcing corner webs will be close to or abutting with the dock frame members at the corner. For especially preferred embodiments of the corner members, the anchoring apertures closest to the corner are spaced from one another by a greater distance than they are along the length. Due to the extra reinforcement at the corner due to the bending connection and the reinforcing corner webs, the corner structure is still sufficiently rigid and durable to withstand the expected heavy bumper functions at this corner.
In especially preferred embodiments, the anchoring apertures through the support webs are disposed laterally offset from one side of the bumper, which side is then provided with additional double reinforcing webs along a short portion thereof, whereby the effective reinforcement across the width of the impact receiving wall is substantially constant, even at the location of the anchoring apertures and anchors. In this manner, a uniform bumper resistance is provided over the full width of the bumper.
Although the preferred embodiments described herein relate to boat dock bumpers, preferred embodiments are also contemplated where the bumper members are mounted at airline terminal baggage carts or other transport vehicles which experience frequent low velocity collisions. At airline terminals, such bumpers can accommodate low speed impact of the baggage carts against airplane parts, without damaging the airplane.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.